Door-opening apparatus for fire-chambers



(No Model.)

P. W. MILLS. DOOR OPENING APPARATUS FOR PIRE CHAMBER-S.

PeLten'nell Mar. 25, 1890.

No. 124,072.l

bowl!! In N, PEYEHS, PhntLilhogr-apher. Wilshinion. DCA

UNITED STATES PATENT EEICE.

FRANK V. MILLS, OF CHICAGO, ILLINOIS.

DOOR-OPENING APPARATUS FOR FIRE-CHAMBERS.

SPECIFICATION forming part of Letters Patent No. 424,072, dated March 25, 1890.

Application filed December 13, 1889. Serial No. 333,617. (No model.)

To all whom ,it Uta/y concern:

Beit known that I, FRANK lV. MILLS, a citi- .zen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a new and useful Improvement in Door-'Opening Apparatus for Fire-Chambers, of which the following is a specification.

The object of my invention is to provide an apparatus, particularly for use in connection with the lire-chamber of a locomotive-boiler, whereby the door may be readily opened by foot-pressure and held open by the fireman while he is throwing coal upon the iire, and which shall operate automatically to close the door on being released froml the foot-pressure. During the operation of iiring, wherein, as is commonly the case, the door of the tirechamber is left open throughout the entire operation, there is a material loss of heat by the cooling effect of the air which thus is permitted to enter. By my improvement this loss is greatly reduced, since by affording, as it does, conveniently operative means for permitting the fireman to open the door each time he throws coal on ,the fire, and which serves automatically to close the door to permit itto remain closed during the intervals, the time for the entrance of the air is obviously very materially lessened.

My improvement, though applicable to steam-engines generally, is shown as applied to a locomotive-engine in the accompanying drawings, in Which- Figure l is a View. in sectional rear elevation of a locomotive having my improved apparatus connected with the fire-chamber door; Fig. 2, a sectional plan View of the same, taken on the line 2 of Fig. l, viewed in the direction of the arrow and enlarged; and Fig. 3, an enlarged view in broken sectional elevation of a detail. Y

A is the steam-boiler, surmounted with the usual dome B, and having the lire-chamber provided witha swinging door C. To one side of the door C is secured a bowl-shaped receptacle D, having its open end or end nearest the door C covered by a diaphragm E, formed of springs or elastic material (preferably soft rubber and canvas in layers) and secured around its edge to that of the mouth of the bowl. A guide-bracket r is secured to the receptacle E in a manner to extend diametrically across the diaphragm, and is provided at its center with a ring o", through which eX- tends a rod F, secured at one end to the diaphragm, as by the means shown in Fig; 2, comprising nuts q, tightened against metal plates p on opposite sides of the diaphragm. Between the ring r and a stop o, I confine a spring n, though the latter is notan indespensable feature of the construction.

To the door C near its hinge is secured an arm Z, having pivotally connected with it one end of a link m, the opposite end being similarly connect-ed with the adjacent end of the rod F.

Below the Hoor G is a chamber H, preferably in the form of a cylinder supported in vertical position, and communicating from its upper end through a conduit 7.: with the steamdome B, the communication being controlled through a suitable valve t', which may be an ordinary plug-valve, and is therefore not necessarily illustrated in detail in the drawings. The plug of the valve t' has secured to it one end of a handle 7L, which is pivotally connected at its opposite end with a rod I, supported to extend vertically normally beyond the upper surface of the iioor Cr, and having a spring f confined around it. The lower end of the cylinder I-I is open to the outer air, and between its ends the cylinder communicates through a pipe q with the `bowl D behind its diaphragm E. n

The operation is as follows: The passage between the chamber H and steam-dome B is normally closed by the position of the valve t' in the conduit K, and the normal condition of the diaphragm is that in which the door C is closed. Then it is desired to open the nre-chamber door, the rod I is pressed and held down (by the fireman when about to replenish the iire with coal) against the spring f, thereby turning the valve t' to open communication between the steam dome and chamber I-I. This permits steam to rush through the cylinder Il past the communication therewith of the pipe c, and, acting :on the principle of the Giffard injector, exhaust the air from behind the diaphragm, creating a partial vacuum in the bowl D sufficiently powerful to draw the diaphragm inward and, through its connection with the doorrC, pull the latter open. As soon as the floor-pressure IOO against the upper end of the rod I is released, the spring f acts to return it to its normal position of protruding beyond the floor G, in moving to which posit-ion it turns the valve/L' to close the passage 7c and permits air to enier the bowl D through the base of the cylinder H and pipe g, destroying the vacuuln and permitting the diaphragm, by the force of its own resistance or by that of the spring n, if employed, or both, to force the rod F forward and push the door shut.

If the valve t' were a spring-valve, as it may be, or if it were maintained normally closed solely by the steam-pressure against it, obviously the spring f could be omitted. Such construction and other changes as to the details shown and described may be provided without thereby departing from my invention.

That I claim as new, and desire to secure by Letters Patent, is-

l. In combination with a tire-chamber door C, a diaphragm E, covering a receptacle D, and connected with the door, a chamber Il, communicating with the open air and with a fluid-pressure supply and intermedately with the receptacle D, a valve/i in the conduit leading to the fluid-pressure supply, and a rod I, connected with the valve, substantially as and for the purpose set forth.

2. In combination with the fire-chamber door C of a locomotive-engine, a diaphragm E, covering a receptacle D and connected with the door, a chamber II, communicating with the open air and with the steam-dome B and intermediately with the receptacle D, a valve 'L' in the conduit leading to the steamdon1e,a rod I, normally protruding beyond the floor of the locomotive-cab, and a handle h, connecting the valve below the floor with the said rod, substantially as and for the pnl'- -pose set forth.

3. In combination with the fire-chamber door C of a locomotive-engine, a diaphragm E, covering a receptacle D, having a guidebracket lr, a rod F, extending from the center of the diaphragm through the guide-bracket and connected with the door C, a cylinder H, supported below the floor G of the locomotive-cab and communicating from one end through a conduit k with the steam-dome B and from its opposite end with the open air, a pipe g, connecting the cylinder from between its extremities with the receptacle D, a valve in the conduit k, having a handle h, and a spring-rod I, normally protruding beyond the floor G and connected with the handle h below the floor, the whole being constructed and arranged to operate substantially as and for the purpose set forth.

FRANK IV. MILLS.

In presence of- J. W. DYRENFORTH, M. J. FRos'r. 

